Fuel cell comprising separator with protrusions in zigzag-pattern

Abstract

A separator of a fuel cell includes a sandwiching section, first and second bridges connected to the sandwiching section, a fuel gas supply section connected to the first bridge and an oxygen-containing gas supply section connected to the second bridge. The sandwiching section sandwiches an electrolyte electrode assembly, and has a fuel gas channel and an oxygen-containing gas channel separately. In the sandwiching section, a plurality of first projections are arranged in a zigzag pattern in a direction in which the first bridge extends, and the first projections at least protrude toward the fuel gas channel to contact an anode.

Description

TECHNICAL FIELD[0001]The present invention relates to a fuel cell formed by stacking electrolyte electrode assemblies and separators alternately. Each of the electrolyte electrode assembles includes an anode, a cathode, and an electrolyte interposed between the anode and the cathode.BACKGROUND ART[0002]Typically, solid oxide fuel cells (SOFC) employ an electrolyte of ion-conductive solid oxide such as stabilized zirconia. The electrolyte is interposed between an anode and a cathode to form an electrolyte electrode assembly (MEA). The electrolyte electrode assembly is interposed between a pair of separators (bipolar plates). In use, generally, a predetermined number of the separators and the electrolyte electrode assemblies are stacked together to form a fuel cell stack.[0003]As the structure of the fuel cell of this type, for example, the fuel cell separator structure disclosed in Japanese Laid-Open Patent Publication No. 63-266777 is known. In the separator structure, a corrugated ...

AI Technical Summary

Benefits of technology

[0009]The present invention solves the problems of this type, and an object of the present invention is to provide a fuel cell in which the desired strength of the separator itself is effectively maintained, the contract area between the separator and the electrolyte electrode assembly is increased, and flowing of the reactant gas without being used is suppressed to achieve improvement in the power generation efficiency.

[0016]In the present invention, in the sandwiching section, a large number of projections are arranged efficiently in comparison with the structure where projections are arranged in a matrix pattern. Thus, with the simple structure, warpage of the separator is suppressed, and the strength against deformation is improved, and improvement in the quality is achieved. Further, since the contact area of the sandwiching section with the electrolyte electrode assembly is increased, the IR losses are reduced, and improvement in the power generation efficiency is achieved. Moreover, since the projections are provided close to each other, flowing of the reactant gas without being used is suppressed, also resulting in the improved power generation efficiency.

Problems solved by technology

However, in Japanese Laid-Open Patent Publication No. 63-266777, since the cutouts are formed in the corrugated plate, the contact area between the separator and the MEA tends to be small.

Therefore, the reactant gas tends to flow through without being consumed, and the power generation efficiency may be lowered undesirably.

Warpage or the like occurs easily in the separator, and the separator is deformed.

WO 00 / 03446, though the projections 2 are arranged in a zigzag pattern on the separator substrate 1, due to the structure of the fuel cell as a whole, it may not be possible to effectively increase the contract area with the MEA.

Thus, improvement in the power generation efficiency cannot be achieved.

Further, it may not be possible to sufficiently suppress warpage of the separator and deformation of the separator.

Therefore, it is difficult to effectively increase the contact area with the MEA.

Further, warpage and deformation of the separator cannot be suppressed, and the reactant gas may flow through without being consumed.

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